Sodium selenide

Sodium selenide
Names
IUPAC name
sodium selenide
Identifiers
1313-85-5 YesY
ChEBI CHEBI:77773 N
EC Number 215-212-0
Jmol interactive 3D Image
PubChem 73973
Properties
Na2Se
Molar mass 124.95 g·mol−1
Appearance white to red solid
Odor unpleaseant
Density 2.625 g cm−3[1]
Melting point 875 °C (1,607 °F; 1,148 K)
reacts with water
Structure
cubic
Thermochemistry
105 J/mol K
-343 kJ/mol
Related compounds
Other anions
Sodium sulfide
Sodium telluride
Sodium oxide
Other cations
Hydrogen selenide
Antimony selenide
Aluminum selenide
Related compounds
Sodium selenite
Sodium selenate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YesYN ?)
Infobox references

Sodium selenide is an inorganic compound of sodium and selenium with the chemical formula Na2Se.

Preparation

This colourless solid is prepared by the reaction of selenium with a solution of sodium in liquid ammonia at -40 °C.[2]

Alternatively, sodium selenide can be prepared by the reaction of gaseous hydrogen selenide with metallic sodium at 100 °C.

Reactions

Like other alkali metal chalcogenides, this material is highly sensitive to water, easily undergoing hydrolysis to give mixtures of sodium biselenide (NaSeH) and hydroxide. This hydrolysis occurs because of the extreme basicity of the Se2− ion.

Na2Se + H2O → NaHSe + NaOH

Similarly, sodium selenide is readily oxidized to polyselenides, a conversion signaled by off-white samples.

Sodium selenide reacts with acids to produce toxic hydrogen selenide gas.

Na2Se + 2 HCl → H2Se + 2 NaCl

The compound reacts with electrophiles to produce the selenium compounds. With alkyl halides, one obtains a variety of organoselenium compounds:

Na2Se + 2 RBr → R2Se + 2 NaBr

Organotin and organosilicon halides react similarly to give the expected derivatives:

Na2Se + 2 Me3XCl → (Me3X)2Se + 2 NaCl (X Si, Ge, Sn)

Safety

Sodium selenide should be stored and handled away from moisture and air.

References

  1. David R. Lide (ed.). CRC Handbook of Chemistry and Physics (90th ed.). ISBN 978-1-4200-9084-0.
  2. Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 1. p. 421.


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